I'd halve the sneak attack progression AND halve the initiator level progression. Then I'd give it access to all nine schools.

Really, what are you going for here? If you keep full sneak attack progression, you can't give it much more than the rogue already has without making it rediculously overpowered. If one hand giveth abilities, the other must take away sneak attack (or skill points, but this is supposed to be a skillmonkey... I guess you could drop the HD like a rock to d4's?)

But, seriously, this is a rogue a scout and a warblade in the same class. O_O